prerequisite check role
fixed formatting, added dns check before creating VM's

Change-Id: Ibb6c8898ca635a4cc6446b8b3aef584fe458c224
diff --git a/cord-single-playbook.yml b/cord-single-playbook.yml
index 48867be..92807f2 100644
--- a/cord-single-playbook.yml
+++ b/cord-single-playbook.yml
@@ -11,6 +11,11 @@
   - include_vars: vars/cord.yml
   - include_vars: vars/example_keystone.yml
 
+- name: Check Prerequisites
+  hosts: head
+  roles:
+    - prereqs-common
+
 - name: DNS Server and apt-cacher-ng Setup
   hosts: head
   become: yes